Enabling water-based EVA adhesives for solvent-free aerosol jet printing in microfabrication

Aerosol jet printing (AJP) is a novel technology which gained significant attention in many fields, as it enabled mask-free material deposition and reduced material waste, compared to traditional methods, while maintaining high resolution, even up to ∼10 μm. This study investigates the use of AJP for the deposition of an aqueous based polymeric emulsion ink (acetate polymer emulsion) for Si wafer bonding application. We first characterized the inks rheological properties, followed by an exploration of the printing process, including the deposition of simple and complex patterns to assess the resolution. The adhesive properties of the printed material were also evaluated. Results have shown that adhesion of the material deposited through AJP was comparable to the one of the material applied through the conventional drop-dispensing method. Our findings demonstrate the feasibility of using AJP for printing polymer inks, expanding the versatility of AJP in various fields, including bonding and temporary bonding applications.